1. Field of the Invention
The present invention relates to an electronic musical instrument suitable for imitating sustaining musical tone generation of, e.g., a bowed instrument, a wind instrument, and the like, and a musical tone control apparatus used in the electronic musical instrument to improve performance expressions of the musical tone.
2. Description of the Prior Art
As an electronic musical instrument which can control musical tone characteristics, such as tone colors, tone volumes, and the like in accordance with an operation velocity, an operation pressure, and the like, an instrument which detects a key depression velocity at a keyboard to control a rising waveform of a musical tone, or detects a key depression pressure during key depression to control a sustaining waveform of a musical tone is known.
In general, in bowed instruments such as a violin, a cello, a viola, and the like, rising and falling timings of a musical tone can be designated by a bowing operation independently of a pitch designation operation by fingers. Furthermore, the bowing operation can be attained in two directions, i.e., bow pull and push strokes, and various expressions can be added to, e.g., rising, sustaining, and falling waveforms of musical tones on the basis of a bow velocity, a bow pressure, and the like in each direction.
In contrast to this, in the conventional electronic musical instrument, a pitch, rising timing, and falling timing of a musical tone are determined by an operation of a key, and rising and falling timings cannot be determined by an operation independently of the pitch designation operation unlike in the bowed instruments. Even when a rising waveform is controlled in accordance with a key depression velocity or when a sustaining waveform is controlled in accordance with a pressure during key depression, since an arbitrary velocity or pressure cannot be designated independently of the key depression operation, a waveform controllable range is limited to a narrow range, and various expressions cannot be added to musical tones unlike in the bowed instruments.
Therefore, the conventional electronic musical instrument is unsatisfactory for imitating musical tone generation of the bowed instruments.
Furthermore, in the conventional electronic musical instrument described above, a key depression velocity is detected by, e.g., measuring a contact shift timing of a switch interlocked with a key. Therefore, only one velocity data can be obtained per key depression operation, and hence, musical tone control according to a change in velocity during operation cannot be performed unlike in a bowing operation. Since a movable range of a key is narrow, a velocity range which can be designated upon key depression is also narrow, and an arbitrary velocity cannot be designated within a wide range unlike in the bowing operation.
In addition, in the conventional electronic musical instrument, although a key depression velocity and a key depression pressure during key depression are reflected in a musical tone, a key operation velocity during key depression cannot be reflected in the musical tone. Therefore, no performance expression by a combination of a pressure and a velocity is available. For example, a velocity cannot be changed while a pressure remains the same, and vise versa.